Answer:
when the ground is very hot and the air is cool.
Explanation:
The hot earth warms a layer of air right above the ground. Light is refracted as it passes through the cool air and onto the hot air sheet (bent). A coating of very warm air near the earth bends the light from the sky almost into a U-shaped bend.
Technically it's a chemical change even though the process is reversible.
Answer:
The force will have to increase
Explanation:
Since Juan has upgraded from a sports car to a large truck, based on Newton's second law of motion, the force needed to keep the truck going at the same speed will have to increase.
According to Newton's second law "the force on an object is equal to the product of its mass and acceleration".
Force = mass x acceleration
A truck has a larger mass compared to a sports car.
By virtue of this, to make sure both automobiles attain the same speed, the force powering them to accelerate must be the same.
Therefore, the force from the engine must increase.
Answer:
An ion is an atom or group of atoms with a positive or negative charge. Ions form when atoms lose or gain electrons to obtain a full outer shell: metal atoms lose electrons to form positively charged ions non-metal atoms gain electrons to form negatively charged ions.
Explanation: